Citation:

ZEPP, R. G., D. J. ERICKSON III, N. D. PAUL, AND B. SULZBERGER. INTERACTIVE EFFECTS OF SOLAR UV RADIATION AND CLIMATE CHANGE ON BIOGEOCHEMICAL CYCLING. PHOTOCHEMICAL AND PHOTOBIOLOGICAL SCIENCES. Royal Society of Chemistry, Cambridge, Uk, 6(3):286-300, (2007).

Impact/Purpose:

The overall objective of this task is to develop quantitative relationships for assessing the vulnerability of aquatic ecosystems (freshwater and coastal) and their services to global change. The task will contribute experimental and modeling tools for assessments of the interactions of global climate and UV changes with coral reefs and selected watersheds and estuaries in the U.S. and Brazil These activities are contributing to two APGs in the ecosystems focus area of the Global Change Research Multiyear Plan: the 2008 APG (APG 2) on developing information and tools that managers will use in their decision-making about how to adapt to the effects of global change on aquatic ecosystems; and the 2010 APG (APG 3) on providing information and models that will support development of biocriteria for corals. One major task objective is to assess interactions of global warming and UV exposure that are contributing to the observed coral bleaching and disease. Our lab is working with scientists at the NHEERL Gulf Ecology Lab to characterize UV exposure and effects at several coral reef sites in the Florida Keys. This collaboration will contribute to one ERD APM in 2006 and three joint NERL-NHEERL APMs in the 2008 - 2010 period. Other research is examining the effects of changing climate and UV on microbial activity in waters close to beaches in the U.S. Work is being completed on the interactions of land use and climate changes with the ecological functioning of streams in watersheds of the southeastern U.S. The task also includes two sub-tasks that are funded mainly by funds-in IAGs. One sub-task funded by NASA involves research in central Brazil that is part of the Large Scale Biosphere Atmosphere Experiment (LBA). This work involves a close collaboration between EPA and a group of scientists from the Department of Ecology, University of Brasilia, Brazil. The objectives of this project are to assess the impacts of land use and climatic changes on soil nutrient cycles and microbiota, trace gas exchange and water quality in the Brazilian cerrado. Another sub-task funded by the Office of Naval Research is examining interactions between nitrogen and organic substances in aquatic ecosystems that produce the colored dissolved organic matter (CDOM) that controls penetration of solar UV radiation into coastal waters.

Description:

This paper assesses research on the interactions of UV radiation (280-400 nm) and global climate change with global biogeochemical cycles at the Earth's surface. The effects of UV-B (280-315 nm), which are dependent on the stratospheric ozone layer, on biogeochemical cycles are often linked to concurrent exposure to UV-A radiation (315-400 nm), which is influenced by global climate change. These interactions involving UV radiation (the combination of UV-B and UV-A) are central to the prediction and evaluation of future Earth environmental conditions. There is increasing evidence that elevated UV-B radiation has significant effects on the terrestrial biosphere with implications for the cycling of carbon, nitrogen and other elements. The cycling of carbon and inorganic nutrients such as nitrogen can be affected by UV-B-mediated changes in communities of soil organisms, probably due to the effects of UV-B radiation on plant root exudation and/or the chemistry of dead plant material falling to the soil.

Record Details: